Think you're a Washington know-it-all? Prove it! Check out our close-up photo—taken somewhere in the Washington area—and try to guess the subject. Plus, see the answer to last week's puzzle.

Leave your guess, including where the subject is located, in the comments. The full photo and location will be revealed with next Tuesday’s puzzle. The winner gets bragging rights.

Last week's puzzle was no problem for commenter sean, who correctly guessed that the photo's subject was the Basilica of the National Shrine of the Immaculate Conception on Michigan Avenue, Northeast. Great job!